title: Synthesis, structure, and photoluminescent properties of metal-organic coordination polymers assembled with bithiophenedicarboxylic acid.
abstract: Four novel metal-organic coordination polymers with the formulas Mn(3)(btdc)(3)(DMF)(4) (1), Co(btdc)(DMF)(3) (2), Zn(btdc)(DMF)(3) (3), and Zn(btdc)(4,4'-bpy)(0.5) (4), where H(2)btdc = 2,2'-bithiophene-5,5'-dicarboxylic acid, DMF = N,N'-dimethylformamide, and 4,4'-bpy = 4,4'-bipyridine, have been successfully synthesized. Crystal 1 with Mn(2+) as the cation features a three-dimensional (3D) infinite framework built from trimanganese clusters, and crystals 2 and 3 with Co(2+) and Zn(2+), respectively, as the cation both have one-dimensional zigzag polymeric coordination chains. Crystal 4 synthesized using a mixture of 4,4'-bpy and H(2)btdc exhibits a triply interpenetrating 3D framework built from a dizinc paddlewheel second building unit with a distorted primitive cubic single net. The results of UV/vis spectra indicate that metal binding does not disturb the detailed electronic structure of the ligand. We also demonstrate that Zn(2+) can greatly enhance the luminescence emission of the H(2)btdc ligand, and the emission intensity of crystal 4 is almost 20 times higher than that of the free H(2)btdc ligand. Steady-state and time-resolved spectroscopic measurement reveal that the more rigid environment of the btdc ligand can stabilize the highly excited long-lived states in metal-organic frameworks (MOFs), which thus greatly changes the emission properties of MOFs.
authors.affiliation: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China.
authors.forename: Jiao
authors.initials: J
authors.lastname: Zhao
authors.forename: Xiu-Li
authors.initials: XL
authors.lastname: Wang
authors.forename: Xin
authors.initials: X
authors.lastname: Shi
authors.forename: Qi-Hua
authors.initials: QH
authors.lastname: Yang
authors.forename: Can
authors.initials: C
authors.lastname: Li
mesh_terms: D003035:Cobalt / Q000737:chemistry; D003998:Dicarboxylic Acids / Q000737:chemistry*; D049449:Luminescence; D008345:Manganese / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D013876:Thiophenes / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry
chemical_list: D003998:Dicarboxylic Acids; D009942:Organometallic Compounds; D011108:Polymers; D013876:Thiophenes; D003035:Cobalt; D008345:Manganese; D015032:Zinc